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A Hand Features Based Fusion Recognition Network with Enhancing Multi-Modal correlation

computer Modeling in Engineering & Sciences 2024年第7期140卷 537-555页

作者： wei wu Yuan Zhang Yunpeng Li chuanyang Li YanHao School of Information Engineering Shenyang UniversityShenyang110044China

Fusing hand-based features in multi-modal biometric recognition enhances anti-spoofing ***,it leverages inter-modal correlation to enhance recognition ***,the robustness and recognition performance of the system can be enhanced through judiciously leveraging the correlation among multimodal ***,two issues persist in multi-modal feature fusion recognition:Firstly,the enhancement of recognition performance in fusion recognition has not comprehensively considered the inter-modality correlations among distinct ***,during modal fusion,improper weight selection diminishes the salience of crucial modal features,thereby diminishing the overall recognition *** address these two issues,we introduce an enhanced DenseNet multimodal recognition network founded on feature-level *** information from the three modalities is fused akin to RGB,and the input network augments the correlation between modes through channel *** the enhanced DenseNet network,the Efficient channel Attention Network(EcA-Net)dynamically adjusts the weight of each channel to amplify the salience of crucial information in each modal *** separable convolution markedly reduces the training parameters and further enhances the feature *** evaluations were conducted on four multimodal databases,comprising six unimodal databases,including multispectral palmprint and palm vein databases from the chinese Academy of *** Equal Error Rates(EER)values were 0.0149%,0.0150%,0.0099%,and 0.0050%,*** comparison to other network methods for palmprint,palm vein,and finger vein fusion recognition,this approach substantially enhances recognition performance,rendering it suitable for high-security environments with practical *** experiments in this article utilized amodest sample database comprising 200 *** subsequent phase involves preparin

关键词： Biometrics multi-modal correlation deep learning feature-level fusion

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understory seedlings of Quercus mongolica survive by phenological escape

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Forest Ecosystems 2024年第2期11卷 236-246页

作者： Shixiong wu Ying Liu Lulu He wei Zeng Qijing Liu college of Forestry Beijing Forestry UniversityBeijing100083China

understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming *** poor regeneration of dominant tree species,however,is one of the biggest challenges it faces at the ***,the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary forests,which contrasts with the extreme abundance of understory seedlings in secondary *** mechanism behind the interesting phenomenon is still *** study used in-situ monitoring and nursery-controlled experiment to investigate the survival rate,growth performance,as well as nonstructural carbohydrate (NSc) concentrations and pools of various organ tissues of seedlings for two consecutive years,further analyze the understory light availability and simulate the foliage carbon (c) gain in the secondary and primary *** suggested that seedlings in the secondary forest had greater biomass allocation aboveground,height and specific leaf area (SLA) in summer,which allowed the seedling to survive longer in the canopy closure *** light availability and positive c gain in early spring and late autumn are key factors affecting the growth and survival of understory seedlings in the secondary forest,whereas seedlings in the primary forest had annual negative carbon *** the growing season,the total NSc concentrations of seedlings gradually decreased,whereas those of seedlings in the secondary forest increased significantly in autumn,and were mainly stored in roots for winter consumption and the following year's summer shade period,which was verified by the nursery-controlled experiment that simulated autumn enhanced light availability improved seedling survival rate and NSc *** conclusion,our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity of high light availability d

关键词： carbon gain Nonstructural carbohydrate Recruitment Trade-off Biomass allocation

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cO2-Induced Modulation of Si-O Bonds for Low Temperature Plastic Deformation of Amorphous Silica Nanoparticles with Enhanced Photoluminescence

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Energy & Environmental Materials 2024年第4期7卷 404-412页

作者： Kang Huang Wenzhuo wu Song Xu Pengfei Yan Zhongming wei Qun Xu Henan Institute of Advanced Technology Zhengzhou University college of Materials Science and Engineering Zhengzhou University State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences

Modulation of Si-O bonds under mild conditions has been a challenging issue in the field of material science,which is critical to manufacture highperformance silica-based optical and photonic ***,we introduce a nondestructive technique to achieve Si-O bond rearrangement,leading to plastic deformation and photoluminescence enhancement of amorphous silica nanoparticles using supercritical carbon dioxides in EtOH/H2O solution under mild temperature.

关键词： amorphous silica anisotropic stress photoluminescence plastic deformation supercritical cO2

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chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral)(PVB) as Elucidated by Solid-State NMR

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chinese Journal of Polymer Science 2024年第1期42卷 113-124,I0010页

作者： Jing Lv Xu chen Zi-Shuo wu Ya-Hui Li wei chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Scienceand Technology of ChinaHefei 230026China

The chain dynamics heterogeneity of the poly(vinyl butyral)(PVB) plasticized by triethylene glycol bis(2-ethylhexa noate)(TEG-EH) was investigated by various solid-state NMR *** plasticized PVB shows two domains in distinct molecular dynamics differences,namely,rigid and soft domains,where the latter is the plasticizer-rich *** time domain low field NMR was first used to investigate the dynamics heterogeneity of the plasticized PVB,and the results show the decreasing activated energy of components in the soft domain of plasticized PVB(E_a=20.2 kJ/mol) as compared with that of the pristine one(E_a=24.3 kJ/mol).Detailed dynamics heterogeneity was obtained by high-field NMR with site-specific *** quadrupole-echo ~2H-NMR was adopted to elucidate the dynamics heterogeneity of the vinyl alcohol(VA) units,where only the hydroxyl group of VA is *** ~1H-^(13)c WISE NMR spectra show that there is not much difference in the mobility of the VB unit in PVB with and without plasticizer,whereas the glass transition temperature differed by approximately 53℃.This is further supported by Torchia's T_1 relaxation *** origin of such an unusual phenomenon is attributed to the critical role of the remaining VA(~22%) in the soft domain,where the VA units locally aggregate through hydrogen ***,the existence of a mobility gradient in the VB unit has been ***,the mobility difference for VB with different stereo-geometry(meso or racemic conformation) is observed for the first *** indicates the importance of modulating the ratio of meso over racemic VB for controlling the macroscopic perfo rmance of PVB.

关键词： Poly(vinyl butyral) Dynamics heterogeneity Plasticizer Solid state NMR

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characteristics of Particulate Matter Emissions for Low-Sulfur Heavy Oil Used in Low-Speed Two-Stroke Diesel Engines of Ocean-Going Ships

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Journal of Thermal Science 2024年第2期33卷 739-750页

作者： wu Gang MA Qianli wei Lijiang JIANG Guohe WANG Tengfei LI Tie Merchant Marine college Shanghai Maritime UniversityShanghai201306China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China

In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various *** samples were collected in situ from the engine exhaust to determine the detailed physical and chemical *** nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(Oc) acc.unts for more than 80% in the HFO particles and leads to an increase in particle *** thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were *** two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 *** morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by *** above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.

关键词： low-speed diesel engine maritime regulations heavy fuel oil TEM particles size and distribution

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Superplastic Tension Behavior of Dissimilar Tc4/SP700 Laminate through Diffusion Bonding

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 353-363页

作者： Qianwen Zhang Tianle Li Yanbin Han wei Zheng Xifeng Li Jianjun wu School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072China AVIc Xi’an Aircraft Industry Group company Ltd Xi’an710089China Institute of Forming Technology and Equipment School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200030China

Superplastic forming is a practical method to manufacture complex-shaped parts of titanium alloys with large *** parts of dissimilar titanium alloys fabricated by superplastic forming can achieve excellent performance by combining the advantages of *** work displays the superplastic tension behavior and microstructural evolution of dissimilar Tc4/SP700 laminate prepared by the diffusion bonding *** titanium alloys can achieve metallurgical bonding at parameters of 800℃/1 h/5 *** for dynamic recrystallization and grain growth behaviors upon superplastic tension,stress-induced phase transformation plays an important role inαtoβphase transformation apart from the elevated *** superplastic deformation can be attributed to the grain boundary sliding accommodated multiplex motion of *** addition,the retained strengths of all dissimilar Tc4/SP700 laminates after superplastic deformation with different strain rates and temperatures range from 807 to 890 MPa.

关键词： Tc4/SP700 laminate Diffusion bonding Microstructure Superplastic tension Strength

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Hovering rotor aerodynamics in extreme ground effect

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chinese Journal of Aeronautics 2024年第7期37卷 204-219页

作者： Zhenlong wu Tianyu ZHANG Huijun TAN Haoyu ZHOU wei cHEN Maixiang XIE college of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China china Aviation Power Machinery Research Institute Zhuzhou 412002China

This paper presents an experimental and numerical study of the aerodynamics of a moderate-scale rotor hovering in the Extreme Ground Effect(EGE)where rotor height-offground is below half the rotor *** tip vortex field was visualized by using the PIV *** aerodynamic performance,tip vortex trajectory,wall jet characteristics,surface pressure and velocity fields were measured and *** explore more deeply the flow mechanisms of the extreme ground effect,Detached Eddy Simulation(DES)was conducted on completely structured *** results showed significant deviations of the rotor performance in EGE from that in Regular Ground Effect(RGE)with the rotor heights of more than half the rotor ***,the flow structures of the rotor in EGE are considerably complex,such as the wall jet and groundwash flow *** rotor wake flow and tip vortices impact the ground more frequently,resulting in distinctive characteristics of the surface pressure and velocity fields in EGE.

关键词： Rotor Ground effect Tip vortex Detached Eddy Simulation(DES) Groundwash

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NicoZn/c@melamine sponge-derived carbon composites with highperformance electromagnetic wave absorption

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2274-2286页

作者： Xiubo Xie Heshan Wang Hideo Kimura cui Ni wei Du Guanglei wu School of Environmental and Material Engineering Yantai UniversityYantai 264005China Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta Shandong University of AeronauticsBinzhou 256603China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

NiMZn/c@melamine sponge-derived carbon(MSDc)composites(M=co,Fe,and Mn)were prepared by a vacuum pump-ing solution method followed by carbonization.A large number of carbon nanotubes(cNTs)homogeneously attached to the surfaces of the three-dimensional cross-linked of the sponge-derived carbon in the NicoZn/c@MSDc composite,and cNTs were detected in the NiFeZn/c@MSDc and NiMnZn/c@MSDc ***_(3)Znc_(0.7),Ni_(3)Fe,and MnO in-situ formed in the NiFeZn/c@MSDc and NiMnZn/c@MSDc *** cNTs in the NicoZn/c@MSDc composite efficiently modulated its complex ***,the composite exhibited the best performance among the composites,with the minimum reflection loss(RL_(min))of-33.1 dB at 18 GHz and thickness of 1.4 *** bandwidth for RL of≤-10 dB was up to 5.04 GHz at the thickness of 1.7 mm and loading of 25wt%.The op-timized impedance matching,enhanced interfacial and dipole polarization,remarkable conduction loss,and multiple reflections and scat-tering of the incident microwaves improved the microwave absorption *** effects of co,Ni,and Fe on the phase and mor-phology provided an alternative way for developing highly efficient and broadband microwave absorbers.

关键词： microwave absorption carbon nanotube element substitution melamine sponge-derived carbon

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Theoretical and experimental investigation of the resonance responses and chaotic dynamics of a bistable laminated composite shell in the dynamic snap-through mode

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 581-602页

作者： Meiqi wu Pengyu LV Hongyuan LI Jiale YAN Huiling DUAN wei ZHANG State Key Laboratory for Turbulence and complex Systems Department of Mechanics and Engineering ScienceBIC-ESATCollege of EngineeringPeking UniversityBeijing 100871China Nanchang Innovation Institute of Peking university Nanchang 330096China Department of Mechanics Guangxi UniversityNanning 530004China

The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic *** existence of the 1:1 resonance relationship between two order vibration modes of the system is *** resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales *** Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are *** discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance *** numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the ***,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare ***,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.

关键词： bistable laminated composite shell dynamic snap-through mode Hopf bifurcation chaotic dynamics vibration experiment

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Enhanced electric-field induced strain in Eu^(3+) doped 0.67BiFeO_(3)-0.33BaTiO_(3) lead-free piezoelectric ceramics

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Journal of Rare Earths 2024年第9期42卷 1747-1754,I0004页

作者： wei Li Tongxiang Liang Xiang He Vyunov Oleg Dongfang Pang Shan wu college of Rare Earths Jiangxi University of Science and TechnologyGanzhou341000China Key Laboratory of High Performance ceramics and Ultrastructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai201800China

Lead-free ferroelectric ceramics,0.67Bi_(1-x)Eu_(x)FeO_(3)-0.33BaTiO_(3)(BF-BT-xEu,x=0-0.02),were prepared via a solid-state reaction,The effect of Eu^(3+) doping on the microstructure,dielectric properties,ferroelectric properties,and electric-field-induced strain was *** X-ray diffraction(XRD) results indicate the presence of a mixed phase of tetragonal and rhombohedral at the morphotropic phase boundary(MPB).Doping with an appropriate amount of Eu^(3+) reduces the Fe^(3+) content and decreases the leakage current in the binary system.A converse piezoelectric coefficient(d_(33)*) of 392 pm/V is obtained at BF-BT-0.003Eu under an electric field of 60 kV/cm at room temperature,which has a curie temperature(T_(c)) of 414℃,The unipolar strain and d_(33)* of BF-BT-0.003Eu ceramics increase to 0.438%and 730 pm/V at 125℃ The field-induced strain response of the BF-BT-0.003Eu ceramics is greater than that of 0.67BF-0.33BT,mainly due to its optimal grain size,reduction of leakage current,and coexistence of ferroelectric-relaxation phases,BF-BT-0.003Eu ceramic is a lead-free candidate for high-temperature actuator applications.

关键词： Ferroelectric Field-induced strain ceramics Lead-free Rare earths

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